Simulated egg yolk and method of making same

ABSTRACT

Simulated egg yolk in the nature of a thermoreversible, preferably homogenized, gel which is non-flowable at room temperature is extruded into disk-like shapes. A restrictive barrier is formed around the egg yolk disks by a reverse method of first contacting the non-flowable yolk with a setting agent such as calcium chloride in water and then with a film former such as sodium alginate in water. The resulting simulated egg yolk looks and behaves like natural egg yolk and may be incorporated into natural egg white while preserving a separate phase, so one can make &#34;sunny side up&#34; and &#34;easy over&#34; eggs.

This application is a Continuation-in-part of application Ser. No.930,105 filed on Aug. 14, 1992, now U.S. Pat. No. 5,227,189, which is aContinuation of application Ser. No. 750,116 filed on Aug. 26, 1991, nowU.S. Pat. No. 5,151,293, which is a Continuation-in-part of applicationSer. No. 551,160 filed on Jul. 11, 1990, now U.S. Pat. No. 5,073,399which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates in general to simulated eggs, includingsimulated egg yolk alone and those dispersed in a separate phase withinliquid natural egg whites to provide simulated raw whole eggs, and moreparticularly, to cholesterol free simulated egg yolks capable ofmaintaining a separate phase in natural egg whites, so that uponcooking, the simulated egg yolk looks and behaves like natural egg yolk;and still more particularly, to such simulated egg yolks in the natureof a room temperature homogenized thermoreversible gel having a lowgelatin content which are encapsulated in a restrictive barrier of anedible cross-linkable water soluble polymer formed in situ.

Although eggs represent an outstanding nutritional food which is enjoyedby many people, especially as part of one's breakfast, the fact is thatnatural egg yolk is one of the richest foods in cholesterol. This hasforced a large number of people who are on cholesterol free diets fromenjoying eating natural whole eggs. One practical and economicallyfeasible solution has been to incorporate a simulated and preferably acholesterol free egg yolk into natural egg white and to preserve them inseparate phases, so that one can make, for example, a "sunny side up"and "over easy" egg. In this regard, there is known in the inventor'sU.S. Pat. No. 5,073,399, which is incorporated by reference herein, asimulated egg yolk and simulated raw whole egg manufactured therewithconstituting an edible liquid, a viscosity modifier which is preferablya positive thermoreversible gel former, and a colorant. The simulatedegg yolks produced thereby, which may be encapsulated by a hydrocolloidrestrictive barrier, are remarkably lifelike and are useful in thepreparation of "sunny side up" and "over easy" eggs when dispersed innatural egg whites.

The inventor realized that in the preparation of a simulated whole rawegg for use in the production of a natural looking "sunny side up" or"over easy" egg, it is typically necessary to store the simulated eggyolk in a separate gelled phase within liquid natural egg white. It wasobserved that these simulated egg yolks tend to absorb water from thenatural egg white, probably by osmosis, thereby undesirably increasingthe weight and volume of the egg yolk. The absorption of water isundesirable because it decreases the viscosity of the egg yolk uponcooking, which adversely results in the reduction of the egg yolk'soverall mechanical and/or physical strength, i.e., the ability to remainunbroken and to retain its integrity and shape prior to beingpurposefully broken after cooking when being eaten. The decrease inviscosity can result in the premature disruption of the structure of thediscrete egg yolk when in the molten state, such as during cooking, anduncontrolled running of the egg yolk at serving temperatures may takeplace. In addition, the reduction in the egg yolk's mechanical and/orphysical strength requires that the egg yolk be handled delicately.

In the inventor's U.S. Pat. No. 5,151,293, which is also herebyincorporated by reference, a number of possible remedies to overcomethese problems of water absorption were proposed. It was observed thatthe positive thermoreversible gel former used in the production of thesimulated egg yolk appeared to be the driving force behind theabsorption of water from natural egg white. Although it was proposed tominimize the amount of gel former used, this also had the tendency ofproducing "delicate" egg yolks whose viscosity will change prematurelysuch that the egg yolk's monolithic structure is lost duringmanufacturing and/or handling, including during cooking. Thus, theproposed solution created other problems which were not fully resolved.

Another proposed method of reducing the initial weight gain of asimulated egg yolk, yet maintaining its viscosity and mechanical and/orphysical strength, is by the use of a restrictive barrier. Severalmethods of imparting such a barrier to the egg yolk before being addedto liquid natural egg white are described, such as a cross-linkedmembrane of an edible resin, e.g. an alginate, a pectin, and the like. Amultivalent cation, such as calcium or aluminum in the form of a saltmay be used as the cross-linking agent. A restrictive barrier can alsobe formed from hydrateable edible polymeric compounds or hydrocolloidswhich give rise to substantial instantaneous increase in viscosity assoon as they come into contact with and start dissolving in aqueoussystems.

Also disclosed is reducing the absorption of water by adding a solute tothe liquid egg white such that smaller osmotic pressure differentialwill exist between the liquid egg white and the simulated egg yolk. Thisis expected to minimize the force thought to be driving water into theegg yolk. Finally, the inventor proposed immersing the egg yolk in anaqueous medium which provides an accelerated tendency of the egg yolk toabsorb water. In this technique, the egg yolk is formulated with lesswater than would otherwise be used. The egg yolk is then immersed intowater until the degree of water absorption desirable has been achieved.When added to liquid egg white, the thus created egg yolk does notexhibit a strong tendency to further absorb water.

Although the '293 patent mentions forming a restrictive barrier layerfrom a cross-linked film of an edible resin, there is no reference to aparticular method of forming the barrier around an egg yolk. The methodsused so far to produce restrictive barriers around simulated egg yolkswere both time consuming and cumbersome. For example, Forkner, U.S. Pat.No. 4,409,249, discusses briefly the use of cross-linked hydrocolloids,such as alginates, with calcium salts, as edible membranes aroundartificial liquid yolks to hold the shape of the egg yolk. Cox et. al.,U.S. Pat. No. 5,192,566, discloses various detailed methods of forming arestrictive barrier around a simulated liquid egg yolk. In both Forknerand Cox et. al. frozen or otherwise immobilized liquid egg yolk iscoated with a restrictive barrier forming solution or dispersion such asone containing edible hydrocolloids, for example, sodium alginate. Thecoated egg yolk is treated to form the restrictive barrier by contactwith a reactive composition in the form of a setting bath containing asetting agent, for example, calcium chloride. Cox et. al. discusses twoalternative methods, the first of which they co-extrude a central yolkportion with a surrounding portion containing the film former, and inthe second they include the film former in the formulation of the yolk.In the preferred method of Cox et. al., the second method, therestrictive barrier forming compounds are mixed with the egg yolkcomponents in sufficient quantities to form a barrier on the outersurface of the egg yolk when contacted with a setting agent. The liquidegg yolk is extruded in the form of discrete liquid globules into asetting bath. These methods are undesirably time consuming, requiringthe yolks to stay in the setting bath for 8-15 minutes, followed byrinsing for about 10-20 minutes.

This conventional process of forming a restrictive barrier in accordancewith either Cox et. al. or Forkner has been found to present a largenumber of disadvantages resulting in a simulated egg yolk having apoorly formed barrier. A major drawback is the commercially undesirable(which may come to the point of being unacceptable) length of timeneeded to complete the process. When attempting to use reasonably shorttimes for the conventional process, additional drawbacks, just tomention a few, include, but are not limited to, irreproducibility of thequality of the membrane, thickness variability, openings in the membranestructure, weak regions which may break easily, and tough to chewregions making the consumption of the respective egg unpleasant.

More particularly, the coating of the egg yolk first with a restrictivebarrier forming compound often results in a barrier which is not onlyflimsy, but also not uniform in thickness. When immersed in the settingbath, the restrictive barrier forming compound often does not cross-linkuniformly, in particular, in those regions having a thicker layer,thereby requiring extended residence times. In addition, it has beenfound that in those regions where an excess of restrictive barrierforming compound is present, incomplete cross-linking may still occur,resulting in the barrier layer being relatively weak, and in fact, maybe in the nature of a loose slurry. These regions are potential defectsites which can cause the simulated egg yolk to prematurely ruptureduring handling.

The setting bath which contains the setting agent, for example, calciumchloride being the major representative of setting agent, even at smallconcentrations is known to have a bitter taste. Any excess setting agentwhich is retained on the egg yolk will subsequently dissolve in theliquid egg whites into which the egg yolk is deposited. This will resultin the finally cooked whole egg having a bitter unpleasant taste whichis unacceptable to the consumer. To avoid this problem, it becomesnecessary to subsequently subject the egg yolk to an extensive rinsebath which is highly undesirable from the standpoint of both processtime and economy.

A further disadvantage is the high probability of a remaining slipperyfluid region under the membrane and surrounding the solid at roomtemperature yolk portion, which fluid region consists of unset orincompletely set film former. All these disadvantages render theseprocesses very delicate, sensitive to unforeseen external parameters,time consuming, and cumbersome. Still more particularly, according tothe conventional method, the yolk is dipped into a solution of a filmformer, which is very viscous even at low concentrations of film former,and therefore it produces an uneven thick film on the yolk. When thisfilm comes in contact with the solution of the setting agent, a thincross-linked skin is formed at the top of the film, away from the yolk.The skin does not allow easy access to the rest of the trapped filmformer, and thus, one has to wait for a long time (many minutes) for thesetting agent, for example calcium ions, to diffuse through the skin andcontinue setting the rest of the resin. This increases the thickness ofthe skin and makes the diffusion process more and more difficult. If onedoes not wait for all the time required to complete the settingthroughout the thickness of the film, there will remain a slippery fluidregion under the skin, adjacent to the yolk, rendering the thus far mademembrane flimsy and not supported by the non-flowable yolk. Further,since the outermost skin of the membrane will be fully cross-linked, dueto the abundance of setting agent in that region, its adhesion to thewhite will be minimal, if any at all, upon cooking the yolk andcoagulating the white. It is a very well known fact that fullycross-linked surfaces are notorious for refusing to adhere to othersurfaces, and they may even be used as release structures. Thus, specialtreatment will be needed to provide adhesion of the membrane to thewhite.

Since the environment at which the membrane was formed in this caseincludes an abundance of setting agent, thorough rinsing becomesnecessary in order to remove the setting agent (calcium chloride, forexample) before the processed yolk is introduced into the egg white. Thetask of removing the setting agent becomes even more difficult, due tothe fact that the portion of setting agent which has been trapped withinthe fully cross-linked outer part of the membrane, and which travelsoutward at a very low speed, does not find any uncross-linked sites tobe bound, and therefore it has to be substantially removed completely toavoid the undesirable taste and other ailments that may introduce to thewhite.

Neither of the aforementioned patents provide a commercially feasiblemethod of manufacturing large quantities of high quality simulated eggyolk and "friable" (either "sunny side up" or "over easy") or"poachable" whole eggs. In the case of U.S. Pat. No. 5,151,293, theproblems of commercializable methods are complicated by attempting tobalance the complexities of water absorption and the need for a strong,monolithic simulated egg yolk with a highly controlledtemperature/viscosity profile (yolk formulated to only become runny andlose its shape when desired).

These problems have been solved by the provision of a commerciallyfeasible mass production method for the formation of high qualitysimulated egg yolk which is extrudable at or below room temperature inaccordance with the present invention. The resulting simulated egg yolk,when added to liquid natural egg white and, thereafter, fried, yields arealistic egg in flavor, texture and look. The resulting egg retains adiscrete egg yolk, even at serving temperatures, which naturally runsupon being disturbed. Thus, the resulting egg product looks, tastes andbehaves as a natural fried or poached egg.

SUMMARY OF THE INVENTION

Applicant has discovered that by completely reversing the steps of theaforementioned conventional process, a membrane lacking the abovediscussed disadvantages can be made. Thus, according to the presentinvention (hereinafter called "reverse method"), a yolk, beingnon-flowable at the temperature of the operation of the process, isinitially coated with the setting agent, and then it is dipped in asolution of the film former, from where it is preferably transferreddirectly to egg white, without the need of rinsing. The whole processtakes but a few seconds, and results in simulated egg yolks of superbquality to those of Forkner and Cox et. al.

Applicant speculates, without this being construed as limiting the scopeof the present invention, that the elimination of the disadvantages ofthe conventional method by using the reverse method are the result ofthe following. Film formers, such as sodium alginate for example, arepolymers which when being in solution give high viscosity. Since thehigher the molecular weight of a given polymer, the stronger and moreintegral films it will produce, one would prefer to use the highestmolecular weight grade available of the given film former.Unfortunately, as the molecular weight increases the viscosity of thesolution also increases. Thus, one has to compromise with regard to filmintegrity of the membrane, viscosity of the solution, and concentrationof the film former in the solution. In any event, dipping a non-flowableobject in such a compromised film former solution, necessarily producesa wet mushy film having rather high and uneven thickness with lowconcentration of film former.

On the other hand, setting agents, such as calcium chloride for example,give very low viscosity when in solution. Thus, dipping of a solid in asolution of a setting agent, produces a very thin and uniform coating,which may also be applied easily by other techniques, such as sprayingfor example.

According to the reverse method of the present invention, the yolk isdipped in a solution of a setting agent, calcium chloride in water forexample, which immediately forms a very thin uniform coating, the lowviscosity being a considerable contributing factor. The thusly coatedegg yolk is in turn dipped into a solution of a film former, such as forexample sodium alginate in water. As soon as the thin and uniformcoating of setting agent comes in contact with the film former solution,a reaction takes place, instantaneously for all practical purposes. Notonly this, but the reaction takes place on the immediate surface of theegg yolk, forming a well supported membrane on a non-flowable substrate.In the case of the reverse method, the very thin, uniform coating ofsetting agent, well supported on the non-flowable yolk, finds itself inan environment of abundant film former. Since there is only a very smallpredetermined amount of setting agent within a very thin film of verylow viscosity, the cross-linking reaction takes place substantiallyinstantaneously in the abundance of the film former. Even if a smallamount of the setting agent does not react immediately, there is plentyof time to react even after the processed yolk has been added to the eggwhite. This is because, as mentioned above, the processed yolk does notneed any rinsing before being added to the egg white, as the viscousunreacted edible polymer solution surrounding now the processed yolkdoes not impart undesirable characteristics to the white.

By the time the viscous unreacted edible polymer (film former) solutiondissolves in the egg white, the remaining traces of the setting agentfind a chance to react with the film former molecules, and thus becomebound. With this process, the fully cross-linked polymer is in directcontact with the egg yolk substantially instantaneously, which gives themembrane highly improved integrity, while the outside of the membranebecomes gradually less and less cross-linked to the point of nocross-linking at all. This configuration provides a membrane having goodadhesion or bonding with the white after cooking, a problem which hasnot been resolved satisfactorily so far with the conventionally mademembranes. It should be noted, however, that if desired, the processedyolk as described above, does not have to be added to the egg whiteimmediately after it has been made.

Other types of application, such as spraying for example, of one or bothcoatings in either, the conventional or the reverse method have similarramifications, producing similar results, respectively. Accordingly, thereverse method of the present invention is considerably superior to theconventional method for producing an edible membrane around a yolk, withregard to a number of attributes, including simplicity, time involved,and quality of product made. The reasons why have not been clearlyestablished. Applicant has provided speculations, which asaforementioned, should not be construed as limiting the scope ofApplicant's invention.

It is one object of the present invention to provide a method ofproducing a simulated egg yolk in the form of an extrudable gel at aboutor below room temperature and which remains solid, discrete andmonolithic in shape during cooking, but behaves as a natural egg yolkwhen the yolk is broken at serving temperatures.

It is another object of the present invention to provide a commerciallyfeasible, highly reproducible, efficient method for producing suchsimulated egg yolks.

It is another object of the present invention to provide a simulated eggyolk in the form of a thermoreversible homogenized gel which does notrequire the presence of a restrictive barrier to maintain its shape.

More particularly, the present invention pursuant to one embodimentprovides a simulated egg yolk comprising a mixture of simulated egg yolkcomponents, the components at least including an edible liquid and apositive thermoreversible gel former, the positive thermoreversible gelformer present in an amount of from about 2.5-9.0 parts per hundredparts by weight of the edible liquid, the egg yolk being a non-flowablethermoreversible homogenized gel at room temperature so as tosubstantially retain its shape until being heated to a highertemperature at which the egg yolk becomes flowable, thereby resembling anatural egg yolk.

In accordance with another embodiment of the present invention there isdescribed a shaped simulated egg yolk comprising a mixture of simulatedegg yolk components, the components at least including an edible liquidand a positive thermoreversible gel former, the positivethermoreversible gel former present in an amount of from about 2.5-9.0parts per hundred parts by weight of the edible liquid, the mixturehaving been heated above room temperature and subsequently having beencooled under continuous mixing until the mixture has formed athermoreversible homogenized gel, the gel having been extruded at atemperature lower than the melting point of the gel into a predeterminedshape to form the shaped simulated egg yolk, the egg yolk beingnon-flowable at room temperature.

In accordance with another embodiment of the present invention there isdescribed a shaped simulated egg yolk comprising a mixture of simulatedegg yolk components, the components at least including an edible liquidand a positive thermoreversible gel former, the positivethermoreversible gel former present in an amount of from about 2.5-9.0parts per hundred parts by weight of the edible liquid, the mixturehaving been heated above room temperature and subsequently having beencooled to form a conventional gel, the conventional gel having beenpureed to form a thermoreversible homogenized gel, the thermoreversiblehomogenized gel having been extruded at room temperature into apredetermined shape to form the shaped simulated egg yolk, the egg yolkbeing non-flowable at room temperature.

In accordance with another embodiment of the present invention there isdescribed a simulated egg yolk comprising a mixture of simulated eggyolk components and a restrictive barrier encapsulating the egg yolk,the barrier formed by coating the mixture first with a setting agent,and then, with a film former which is reactive with the setting agent toform the barrier.

In accordance with another embodiment of the present invention there isdescribed a simulated egg yolk comprising a mixture of simulated eggyolk components, the mixture being in the form of a nonflowablehomogenized gel at about room temperature.

In accordance with another embodiment of the present invention there isdescribed a method of making a simulated egg yolk comprising preparing amixture of simulated egg yolk components and encapsulating the mixturewith a restrictive barrier, the barrier formed by coating the mixturefirst with a setting agent, and then, with a film former which isreactive with the setting agent to form the barrier.

In accordance with another embodiment of the present invention there isdescribed a method of making a simulated egg yolk comprising preparing amixture of simulated egg yolk components; heating the mixture above roomtemperature; then cooling the heated mixture in accordance with thesteps selected from the group consisting of (i) while cooling themixture continuously mixing the components until the mixture forms ahomogenized gel, and (ii) until the mixture forms a conventional gel,and then pureeing the conventional gel in a manner to form a homogenizedgel; and shaping the homogenized gel to form the simulated egg yolk.

In accordance with another embodiment of the present invention there isdescribed a method of preparing a simulated raw whole egg comprising thesteps of:

(a) making a mixture comprising water, gelatin having a bloom value inthe range of 200 to 300 in an amount of from about 2.5-9.0 parts perhundred parts by weight of the water, freeze-thaw stable starch in anamount of from about 6.0-12.0 parts per hundred parts by weight of thewater, fat free milk solids in an amount of from about 4.0-8.0 parts perhundred parts by weight of the water, a colorant, and optionally aflavor;

(b) raising the temperature of the mixture until the gelatin isdissolved and the starch is hydrated;

(c) optionally adding egg white in an amount equivalent to about2.5-10.0 parts of egg white solids per hundred parts of water, theaddition being made after the temperature of the mixture has droppedbelow the coagulation temperature of the egg white;

(d) forming a positive thermoreversible homogenized gel by following aset of steps selected from the group consisting of cooling the heatedmixture to a temperature under 50° F. while continuously mixing untilthe homogenized gel has been formed, and cooling the heated mixtureuntil the mixture forms a conventional gel, and then pureeing theconventional gel in a manner to form the homogenized gel;

(e) extruding the positive thermoreversible homogenized gel to form diskshaped simulated yolks;

(f) applying a coating comprising calcium ions on the simulated yolks;

(g) applying an additional coating comprising sodium alginate on theyolks of step (f), the calcium ions setting the sodium alginate to forma restrictive barrier; and

(h) adding the yolks of step (g) to egg white.

In accordance with another embodiment of the present invention there isdescribed an apparatus for encapsulating a simulated egg yolk with arestrictive barrier, the apparatus comprising means for extruding amixture of simulated egg yolk components in the nature of a gel into asimulated egg yolk of predetermined shape, a first bath containing asetting agent, a first support having at least one portion thereofwithin the setting agent for receiving thereon the simulated egg yolk, asecond bath adjacent the first bath containing a film former which isreactive with the setting agent to form the barrier, and first means forsliding the simulated egg yolk across a surface of the first supportfrom within the setting agent in the first bath into the film former inthe second bath.

BRIEF DESCRIPTION OF THE DRAWINGS

The above description, as well as further objects, features andadvantages of the present invention will be more fully understood withreference to the following detailed description of a simulated egg yolkand method of making same, when taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a diagrammatic illustration of an apparatus for extrudingsimulated egg yolk material in the form of a thermoreversible gel into apair of baths containing a setting agent and a film former,respectively, for forming a restrictive barrier layer thereon;

FIG. 2 is a diagrammatic illustration of a wire cutter for cutting theextruded simulated egg yolk material into flat disk-like patties and thelike;

FIG. 3 is a diagrammatic illustration of a portion of an assembly foradvancing patties of extruded simulated egg yolk material along aninclined plate-like support from within one bath to another; and

FIG. 4 is a diagrammatic illustration of the activating switches foroperation of the apparatus of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Liquid "simulated egg yolk components" as used herein are the componentsfrom which the simulated egg yolk in accordance with the presentinvention is produced. Generally, these simulated egg yolks include theformulations described in the inventor's aforementioned U.S. Pat. Nos.5,073,399 and 5,151,293 including an edible liquid, a viscosity modifierin the nature of a gel former, a viscosity builder in the nature of astarch and a coloring agent. Preferably, however, the formulation willinclude non-fat dry milk, starch, gelatin, optionally salt, natural eggflavor, beta carotene, water and/or one or more compounds of real egg.As disclosed in the aforementioned patents, other ingredients can beadded as desired.

Liquid "natural egg white" or "egg white" as used herein generallyrefers to preferably naturally occurring egg white derived from chickeneggs. Of course, the egg white may be synthetic and/or can include otheringredients. For example, a gum can be added to the liquid egg white,particularly previously pasteurized liquid egg white, to adjust itsviscosity. However, there is no requirement that the egg white includeany such ingredients.

The simulated egg yolk of the present invention is constituted from amixture of components, at least one of which being a viscosity modifierwhich is present at relatively low percentages, yet providing anonflowable extrudable gel at room temperature so as to substantiallyretain its shape until being heated to a higher temperature at which theegg yolk becomes flowable. The viscosity modifiers are those materialsknown as positive gel formers, and preferably those which arethermoreversible, and negative gel formers, and preferably those whichare nonreversible. A preferred example of a positive thermoreversiblegel former is gelatin which is obtained from a collagen found in animaltissues, including the skin, tendons, and ossein of bones. Gelatin iscommercially available under the mark KNOX which is sold by KnoxGelatin, Inc., Englewood, N.J. Examples of other companies offeringgelatin are Horbel, Lebanon, N.J., Germantown Manufacturing Company,Broomall, Pa., and Atlantic Gelatin, Woburn, Mass.

The central role of the viscosity modifier is to provide the simulatedegg yolk with the ability to preserve its desired shape during itsmanufacture and during the period of time the egg yolk is stored andhandled while being in liquid egg white. In order to prevent excessivewater absorption during prolonged storage of the simulated egg yolk innatural egg white, it is preferred that the simulated egg yolkcomponents include a rather small, but still effective amount ofthermoreversible gel former, such as gelatin, for example. The usefulrange of gelatin will be in the range of from about 2.5-9% by weight ofthe edible liquid present, and preferably from about 3-6% by weight ofthe edible liquid, and most preferably between 3.0-4.0% by weight of theedible liquid.

At gel levels below about 2.5% by weight of the edible liquid, it iscontemplated that the simulated egg yolk would be rendered excessivelyweak making it difficult to handle and maintain intact. Due to theinherent weakness of the egg yolk resulting from the low gelatinpercentage, a number of known processes for forming the shaped egg yolkare not feasible.

For example, in the conventional molding process, when the egg yolkcools, it expands making it difficult to remove from the mold. Inaddition, evaporation of water from the surface of the yolk causesconsiderable sticking of the yolk to the mold at the common boundary ofthe mold, the environmental air, and the yolk surface. Furthermore, thesubstantially perfectly smooth interface between the yolk and the moldproduces vacuum at said interface which hinders the separation of theyolk from the mold. Removing the egg yolk without damage is renderedeven more difficult due to the inherent weakness of the egg yolk. In astarch molding process, powdered starch is compacted to form individualmolds to receive the liquid simulated egg yolk. After cooling, thecompacted starch is separated from the molded simulated egg yolk bytumbling through sieves. This tumbling has rendered the starch processgenerally impractical for use with simulated egg yolks having a lowgelatin content due to their inherent weakness.

Notwithstanding the low gelatin content, it has been found possible toconvert the liquid simulated egg yolk from its heated condition into anextrudable gel at about or below room temperature in accordance with thepresent invention. By "thermoreversible homogenized gel" in accordancewith the present invention, it is meant:

(1) the composition of the "thermoreversible homogenized gel" is suchthat it forms a "conventional gel" (having an appearance similar to thatof "jello", for example), when the formation takes place in asubstantially static mode, i.e., without substantial mixing, by coolingthe composition from a higher temperature, at which temperature thecomposition is flowable and pourable, to a lower temperature at whichgelation takes place in a period of time;

(2) the formation of the "thermoreversible homogenized gel" takes placeby stirring or mixing, such as for example by pureeing, the gel duringsubstantially the whole period the gel is being formed, or after thegelation process has been completed or both; and

(3) by reheating to an appropriately higher temperature, the"thermoreversible homogenized gel" takes the form of a flowable andpourable composition again.

A material is considered to be non-flowable if for all practicalpurposes it does not flow under its own weight in the practice of thepresent invention. The "thermoreversible homogenized gel" has a somewhatduller appearance than a "conventional gel" of the same composition.While maintaining the basic non-flowable gel character, when anadequately high spreading force is applied onto it, the gel spreadsuniformly, without breaking into discrete pieces, and thus it may beextruded uniformly through a die with substantially no deformationsaround the borders of the die, in contrast to a "conventional gel",which forms non-uniform extrudates, unless special care has been takento include a pureeing stage before the final extrusion through the die.It appears that the "thermoreversible homogenized gel" yields to lowerstresses than a "conventional gel" of the same composition, and itspreads uniformly.

Although the "thermoreversible homogenized gel" is considerably stickierthan a "conventional gel" of the same composition, it loses itsstickiness when brought in contact with a liquid or a powder. Actually,when it comes in contact with a liquid, it becomes very slippery, andtherefore, very easy to handle, even by sliding onto a preferably wetsolid surface.

A substantial advantage in using a "thermoreversible homogenized gel" inplace of a "conventional gel" in the manufacture of the artificial yolksof the present invention, is that it provides a number of properties ofutmost importance to the yolks:

(1) the yolks melt considerably more uniformly throughout their mass,thus providing a highly improved product;

(2) they melt considerably faster throughout their mass, thus allowingthe yolk to melt completely by the time the white is fully cooked byfrying, for example, without the need to turn the egg over, or to pourhot oil over the yolk;

(3) even if the yolk has not been melted completely, for any reason atall, the mouthfeel of the yolk is not objectionable, since, as believedby Applicant without this to imply any limitations to the scope of thisinvention, the gel structure yields easily in the mouth, and it meltsfaster and uniformly; and

(4) without direct proof, and without this to imply any limitations tothe scope of this invention, Applicant believes that the homogenizedyolk tends to absorb less water upon prolonged contact with egg-white,due to the fact that the homogenized or broken structure of the"thermoreversible homogenized gel" has a considerably lower degree ofmembrane-like configuration than a "conventional gel" of the samecomposition, so that the osmotic pressures forcing water into the yolkare minimized.

In addition to the above, when the compositional parameters of preferredembodiments of the present invention are followed, the yolks attainfurther highly beneficial characteristics, such as

(1) they stay in the molten state for a considerably longer time afterthey have been cooked;

(2) even if they re-solidify because of prolonged standing, andtherefore cooling to room temperature, after they have been cooked, themouthfeel does not become objectionable; and

(3) water absorption is further minimized when the yolk has remained forprolonged periods of time in contact with the liquid egg-white.

In accordance with the present invention, a simulated egg yolk in thenature of an extrudable, thermoreversible homogenized gel at or belowroom temperature having a low gelatin content will now be described. Thesimulated egg yolk of the present invention comprises a mixture ofcomponents, including an edible liquid, viscosity modifier, and acolorant. The edible liquid is preferably aqueous, with the option ofhaving different ingredients dissolved, emulsified, or dispersedtherein. Examples of edible liquids are water and milk, among manyothers. The viscosity modifier, which provides a major part of thefunctions characterizing the egg yolks of the present invention, may bea single ingredient such as gelatin, or a combination of ingredients,each ingredient fulfilling at least partially the needs of a desiredproperty. The viscosity modifier may be natural or artificial, intrinsicto the edible liquid, or external and added to the liquid. It may bealso be a simple compound, or a mixture of compounds. It is onlyimportant that it provides desirable properties and flow characteristicsaccording to the present invention. The colorant, if it has a yellowishcast, is necessary to make the simulated egg yolk resemble a real one,and in general, when it has any color at all except white, to make theegg yolk visibly distinguishable from the egg white. Thus, it may have ayellowish cast as known from beta carotene, or any other color forspecial effects.

In addition to the viscosity modifier, a simple viscosity builder mayalso be added to the mixture of ingredients. Starches and gums ingeneral are examples of viscosity builders, which however, does notexclude them from being on certain occasions also gel formers. Theimportant difference that a viscosity modifier such as gelatin, ascompared to a simple viscosity builder such as starch may provide to theegg yolk is that the viscosity modifier gives a considerably more suddenviscosity change around a temperature range called gel or melting point,while the latter lacks such a well defined point, and the viscositychanges are rather gradual. The preferred viscosity builders accordingto this invention are starches, and especially freeze-thaw stablestarches, such as Freezist M, for example, from Staley, Decatur, IL.

Milk, preferably of the low-fat type, and more preferably of the non-fattype may be used as an additional ingredient in the composition of thesimulated egg yolk of the present invention. The milk provides flavor,texture, opacity, and it may decrease syneresis or water separation, aswell as being an additional source of protein. Its use in theformulation of the yolk of the present invention is highly desirable. Inaddition to these basic ingredients, a number of other ingredients suchas oils, preferably unsaturated vegetable oils, may be used tocomplement the composition of the egg yolk, and emulsifiers foremulsifying the oils or for any other purpose. Typically, when milksolids are present, they may be used as an emulsifier for the oil orother hydrophobic substances. Miscellaneous other ingredients, such asvitamins, minerals, stabilizers, antioxidants, or pacifiers, and thelike, well recognized and utilized in the art of food products may alsobe used to impart the respective desirable functions. Other specificingredients useful in the preparation of a simulated egg yolk inaccordance with the present invention are described in the '399 patent,which ingredients are incorporated herein by reference.

Broadly in accordance with the present invention, the requisiteingredients to form a simulated egg yolk in accordance with the presentinvention may be blended under agitation to a temperature in the rangeof 160°-180° F., within a jacketed kettle, for sufficient time until allingredients are dissolved and no further substantial change in viscosityis observed. By way of example, the mixture is blended at its elevatedtemperature for about 5 to 20 minutes while the mixture attains a finalviscosity in a way that is flowable. After attaining the finalviscosity, the mixture of ingredients while being constantly agitated iscooled preferably using ice water or other suitable coolant until themixture attains the consistency of an extrudable, non-flowablethermoreversible homogeneous gel. The extrudable gel is attained at atemperature of the mixture at approximately room temperature or below,wherein the mixture noticeably changes from a shiny to dull appearance.The mixture may be further cooled to a temperature in the range of from32°-65° F. The time required to achieve the consistency of thehomogenized gel decreases with temperature. In the absence of coolingwith ice water, for example, the time at about room temperature, for thecomposition to change from a shiny appearance to dull is considerablylonger to that needed if the mixture were cooled with ice water, forexample, to a temperature lower than room temperature, such as 40°-50°F., for example.

Important to the formation of the low gelatin containing composition asan extrudable mixture is the setting of the mixture under continuousstirring while cooling. The ability to attain a uniform extrudable gelis contemplated to be the result of the continuous stirring whilesetting the mixture which prevents the formation of a highly branchedgelatin network. Although the extrudable egg yolk mixture has arelatively high viscosity rendering the yolks non-flowable, such eggyolks become flowable when heated to cooking temperatures. The simulatedegg yolk material may be stored at refrigerated temperatures prior tobeing extruded into individual egg yolk shapes, and subsequentlyencapsulated with the restrictive barrier.

Alternatively, the yolk mixture may be cooled under static conditions toform a conventional gel, and then pureed to form a homogenized gelaccording to this invention.

The baths of the cross-linkable edible resin (sodium alginate, forexample) and the cross-linker (calcium chloride, for example) maypreferably be maintained at about room temperature or below roomtemperature, and above freezing of the solutions.

As apparent from the description of the present invention, thecomposition of a low-gelatin containing simulated egg yolk may varygreatly qualitatively and quantitatively as to individual ingredients.The following examples are thus considered to be illustrative of usefullow gelatin containing simulated egg yolk compositions in accordancewith the present invention.

EXAMPLE I

    ______________________________________                                        INGREDIENTS          % BY WEIGHT                                              ______________________________________                                        Freezist M (Starch)  30                                                       Non-fat Dry Milk     17                                                       Gelatin              7.5                                                      1% Beta-Carotene (Water Dispersible)                                                               2.5                                                      Flavor               0.5                                                      Water                220.0                                                    ______________________________________                                    

PROCEDURE

The dry ingredients were premixed together to form a homogeneous mixtureprior to being added to the water at about room temperature. The mixtureof simulated egg yolk components were gently heated under agitation to afinal temperature of about 160° F. Once the viscosity of the mixturestabilized as evident by no further thickening, the mixture was cooledin an ice bath under continuous agitation until the mixture attained theform of an extrudable thermoreversible homogeneous gel as evident by adull appearance at a temperature of about 50° F. The mixture wassubsequently extruded and encapsulated with restrictive barrier as to bedescribed hereinafter.

EXAMPLE II

It was discovered by the inventor that by replacing some of the water inthe composition with natural egg white, the whole eggs when fried, couldbe turned over with lower probability of running of the egg yolk. Ofsignificance it was discovered that although the egg yolks containing aquantity of natural egg white had a consistency similar to those made inaccordance with Example 1, they became less viscous with time, even inthe absence of any water as when dispersed in the natural egg white.This has the benefit of enabling the shaping of a simulated egg yolk inthe form of a disk, which after being encapsulated with a restrictivebarrier, attains lower viscosity without absorbing water or changing itsvolume, or bursting, and one which behaves more like a real egg yolk,depending on the amount of natural egg white present. An illustrativecomposition of the foregoing is as follows:

    ______________________________________                                        INGREDIENTS          % BY WEIGHT                                              ______________________________________                                        Freezist M (Starch)  30                                                       Non-fat Dry Milk     17                                                       Gelatin              7.5                                                      1% Beta-Carotene (Water Dispersible)                                                               2.5                                                      Flavor               0.5                                                      Water                165.0                                                    Egg White            55.0                                                     ______________________________________                                    

PROCEDURE

The procedure of Example I was followed, except for the addition of thenatural egg white. The mixture was heated under agitation until nofurther thickening occurred. The mixture was then cooled in an ice bathunder constant agitation until the temperature dropped to below thecoagulation of natural egg whites, about 140° F. At this point, the eggwhite was added, and the cooling of the mixture under continuousagitation was continued as in Example I.

EXAMPLE III

The composition of Example II was cooled without stirring, and placed ina conventional cookie extruder in a refrigerator overnight. Thefollowing day, when the composition was extruded, a very non-uniform andcurly extrudate was obtained. However, by taking the same compositionout of the extruder, pureeing it well with a spatula, thus breaking thegel's structure, the composition was extruded to obtain a goodextrudate. Similar results were obtained from the composition of ExampleI.

An apparatus for making a simulated egg yolk in accordance with thepresent invention will now be described with reference to FIGS. 1-4,wherein like referenced numerals represent like elements. Referringspecifically to FIG. 1, the apparatus includes a piston extruder 10constructed in the form of a longitudinally extending hollow cylinder 12of uniform diameter having an air inlet 13 adjacent its upper end. Oneend of the cylinder 12 communicates with a T-shaped extension 14 ofsmaller diameter. The extension 14 includes a straight-through conduit16 controlled by a valve 18, and a transversely arranged conduit 20controlled by a valve 22. Preferably, valves 18 and 22 are of theball-valve type. The mouth of the straight-through conduit 16 may besized and shaped for the shape of the particular extrusion of thesimulated egg yolk desired. In the alternative, a suitable die may beremovably secured thereto such as via threads and the like.

Positioned adjacent the mouth of the straight-through conduit 16 is areciprocal knife assembly 24 as best shown in FIG. 2. The knife assembly24 includes an air cylinder 26 having a moveable cylinder rod 28 towhich there is connected a U-shaped bracket 30 having a cutting wire 32stretched across and attached to the opening thereof. Received withinthe other end of the cylinder 12, is a piston 34 attached to a shaft 36which is operatively coupled to a linear driving mechanism 38. Thedriving mechanism 38 is, in turn, connected to an actuating lever 40which is operated by an air cylinder 42 having a cylinder rod 43.

Directly underlying the piston extruder 10 is a first container 44 whichcontains an inclined support 46 in the nature of a smooth planar platehaving an uninterrupted surface. The support 46 is arranged at anincline so as to extend over a sidewall of the container 44 via adownwardly bend extension 48. Overlying the first container 44 is amoveable first pusher 50 as best shown in FIG. 3. The first pusher 50includes an extension 52 which rests on the surface of the support 46and includes a generally elongated central opening 54. The extension 52may be higher than the one illustrated in FIG. 3, it may be perforated,or it ma be made of screen material, or bent wire, and the like, inorder to allow free movement of liquid therethrough. The first pusher 50is connected to an air cylinder 56 by means of a first arm 58. Byoperation of the air cylinder 56, the extension 52 of the first pusher50 is slid upwardly across the surface of the support 46. Excess settingsolution 60 within the first container 44 is allowed to flow through theopening 54 so as not to be dragged out of the container.

A second container 62 is positioned adjacent the first container 44 andis similarly constructed. In this regard, the second container isprovided with an inclined support 46' underlying a second moveablepusher 50'. The second container 62 is filled with a film formingsolution 64. Positioned adjacent the second container 62 and underlyingthe bend extension 48' of the support 46' is a third container 66containing a quantity of liquid egg white 68.

Not shown in FIG. 1 for purpose of clarity, the first container 44containing the setting solution 60 and second container 62 containingthe film forming solution 64 are provided with liquid level controldevices and filtering devices. When the liquid level within therespective first and second containers 44, 62 falls below a certainpredetermined level, fresh solution, i.e., setting solution or filmforming solution, is added from a respective larger reservoir. Thesetting solution 60 and film forming solution 64 are also pumpedcontinuously or intermittently through appropriate filters for removingsmall egg-yolk pieces, gels, etc. using a peristaltic pump or the like.Finally, the limiting and/or activating switches as shown in FIG. 4 willbe described with reference to the process for extruding the simulatedegg yolk material and forming a restrictive barrier thereon.

Simulated egg yolk material, such as prepared pursuant to Examples I-IIIis pumped at a temperature in a preferable range of 32°-65° F. throughconduit 20 into the interior of the cylinder 12 with valve 22 open andvalve 18 closed. The air inlet 13 at the top of the cylinder 12 preventsair from being entrapped under the piston 34 as the simulated egg yolkmaterial 70 fills the cylinder. When the cylinder 12 has been filled tothe level of the piston 34, valve 22 is closed and valve 18 within theconduit 16 is opened.

Every time actuating lever 40 is raised by operation of air cylinder 42,the shaft 36 is pushed downward displacing the piston 34 a predetermineddistance. As the piston 34 is displaced longitudinally within thecylinder 12, a predetermined quantity of simulated egg yolk material 70is extruded from opening 72. The return of actuating lever 40 to itsinitial position has no effect on movement of the shaft 36. When theappropriate amount of simulated egg yolk material 70 has been extrudedthrough opening 72, the knife assembly 24 is activated via air cylinder26 such that the cutting wire 32 cuts through the simulated egg yolkmaterial 70 forming an egg yolk disk 74, which falls into the underlyingfirst container 44 containing the setting solution 60, e.g., 4% calciumchloride and water. The wire cutting 32 of the knife assembly 24 beginscutting the simulated egg yolk material 70 at location 76 which is atthe beginning of the opening 72, and stops cutting at position 78, whichis at the end of the opening.

The egg yolk disk 74 falls through the setting solution 60 onto thesupport 46. Activation of the first moveable pusher 50 by means of aircylinder 56 causes the egg yolk disk 74 to be slid upwardly across thesurface of the support 46 by engagement with extension 52. The egg yolkdisk 74 is slid over the bend extension 48 of the support 46 whereuponit falls into the underlying second container 62 containing film formingsolution 64, which is a cross-linkable polymer, e.g., 1% Keltone HV(from Kelco, Clark, NJ) which is high viscosity sodium alginate, andwater. As the extension 52 breaks the surface 80 of the setting solution60, the excess setting solution will drain back into the first container44 through the opening 54 within the extension. In a similar manner, thesecond moveable pusher 50' advances the egg yolk disk 74 across thesupport 46' and out of the film forming solution 64 until it reaches thebend extension 48' where it falls into container 66 containing theliquid egg white 68 for packaging therewith.

Referring to FIG. 4, there is shown the air cylinders 24, 42, 56 and56', as well as limiting switches represented by small rectangles with anumber and single letter beside the switches. The number indicates theair cylinder to which an action will take place when the switch underconsideration is pushed. The letter shows whether the air cylinder willadvance (A) or will reverse (R) its arm during operation. All aircylinders are double acting by arrangements very well known in the art.They are activated by a temporary closing of a respective switch, andare provided with special valves which may regulate accurately theadvancing or reversing speed of the respective arms of the air cylinders26, 42, 56 or 56'. Air cylinders 26 and 42 are arranged to normally havetheir arms reversed, while air cylinders 56 and 56' are arranged tonormally have their arms advanced.

The operation of the air cylinders 26, 42, 56 and 56' vis-a-vis theactuating switches with respect to the extrusion of simulated egg yolkmaterial 70 into egg yolk disks 74 to which a restrictive barrier isformed thereon will now be described. By using an overriding switch (notshown) a signal is given to air cylinder 42, which advances its cylinderrod 43 in a fast mode. As cylinder rod 43 advances, it first pushesactuating lever 40 upward so that the extrusion of the simulated eggyolk material 70 is initiated by advancement of the piston 34 within thecylinder 12. The position of the air cylinder 42 is arranged (by aconventional screw-type raising and lowering mechanism, not shown forpurposes of clarity) such that when the cylinder rod 43 is fullyextended, a predetermined amount of the simulated egg yolk material 70is extruded through opening 72. At this point, a set S1 of two switchesis activated. Activation of the first switch 42R causes cylinder rod 43of air cylinder 42 to quickly reverse to its normal position as shown inFIG. 1. Activation of the second switch 26A causes cylinder rod 28 ofair cylinder 26 to advance so that (i) the time it takes for the cuttingwire 34 of the knife assembly 24 to reach initial position 76 issufficient for the simulated egg yolk material 70 which has beenextruded through the opening 72 to have reached volume equilibrium, (ii)the time it takes for the cutting wire 34 to advance from initialposition 76 to final position 78 is sufficient to produce a cut withoutback-sticking, and (iii) the time it takes for the cylinder rod 28 toreach the set S2 switches is sufficient to allow the egg yolk disk 74 tofall into the first container 44 containing the setting solution 60. Itis preferable that the switch 26A is activated before the switch 42R hasbeen activated in order to ensure the activation of both switches. Thisis because if switch 42R is activated prematurely causing the cylinderrod 43 to reverse to its initial position prematurely, the switch 26Amay not find a chance to be activated. This in turn would causeinterruption of the operation.

Activation of set S2 of switches 56R and 26R causes cylinder rod 28 ofair cylinder 26 to quickly reverse, coming to its normal rest position,and also causing arm 58 of air cylinder 56 to reverse slowly. Thiscauses the extension 52 to slowly slide the egg yolk disk 74 upwardlyalong the surface of the support 46 until at the bend extension 48, theegg yolk disk falls into the second container 62 containing the filmforming solution 64. Again, switch 56R should be activated before switch26R to ensure uninterrupted operation. After ensuring that the egg yolkdisk 74 has fallen into the second container 62, the arm 58 of the firstmoveable pusher 50 activates the set S3 of switches 42A, 56A, and 56'R.Again, switch 56A should be activated last in order to ensureuninterrupted operation. This causes (i) the first arm 58 to advancequickly to its normal position, (ii) second arm 58' of the secondmoveable pusher 50' to reverse slowly so that the second extension 52'slides the egg yolk disk 74 upwardly across the surface of the support46' and out of the film forming solution 64 until the disk falls overthe bend extension 48' and into the third container 66, and (iii)cylinder rod 43 of air cylinder 42 to rapidly advance, thusautomatically starting a new extrusion cycle. In the meantime, secondarm 58' of air cylinder 56' , which has already caused the egg yolk disk74 to fall into third container 66, reaches set S4 of a single switch56'A which causes second arm 58" to advance quickly to its normalposition.

The following examples are considered illustrative of forming arestrictive barrier on extruded disks of simulated egg yolk material inaccordance with the apparatus of the present invention as thus fardescribed.

EXAMPLE IV

Formation of Restrictive Barrier

A first bath was prepared by dissolving 4 parts of anhydrous calciumchloride (setting agent) in 96 parts of water by weight.

A second bath was prepared by dissolving one part of Keltone HV (highviscosity sodium alginate from KELCO, as film former) in 99 parts ofwater by weight.

A homogenized gel was prepared as described in Example I, and fed intoan extruder. In sequence, the homogenized gel was extruded andsimultaneously wire-cut into disks having a thickness of about 1/4 and adiameter of about 11/2. Each disk was arranged to fall into the firstbath on an inclined first support at a rate of 1 yolk per 5 seconds. Theinclined first support had a portion extending over the second bathwhich contained the solution of the film former. After each yolk fell onthe first support, it was forced to slide on the first support and fallinto the second bath (containing the film former) on a second support.The yolk was once again forced to slide on the second support and fallinto a container containing egg white. The residence time of the eggyolk in each of the two solutions can be adjusted, and is typically inthe range of from about 1 to 5 seconds, and more preferably in the rangeof from about 1 to 3 seconds. The whole operation of forming therestrictive barrier took place at room temperature.

EXAMPLE V

The same procedure was followed as described in Example IV, with thedifference that the homogenized gel was extruded at a temperature of45°-55° F.

EXAMPLE VI

The same procedure was followed as described in Example IV, with thedifference that the first and the second baths were maintained at atemperature of 45°-55° F.

EXAMPLE VII

The same procedure was followed as described in Example IV, with thedifference that the operation of forming the restrictive barrier tookplace at a temperature of 45°-55° F.

EXAMPLES VIII, IX, X, AND XI

Some of the eggs produced according to Examples IV, V, VI, and VII, werefried on a grill in a sunny-side-up mode, just using a spray release(PAM, sold in supermarkets) on the grill. The yolks were fully molten bythe time the white was just fully cooked, without any signs of it beingovercooked, or burned.

EXAMPLE XII

A number of eggs were made as described in Example IV, with thedifference that instead of using the homogenized gel of Example I, thehomogenized gel of Example II was used.

EXAMPLE XIII

A number of simulated whole eggs made as described in Example IV werefried on one side, and then they were turned over. In some cases theyolk did not break, and in some cases it broke.

EXAMPLE XIV

A number of simulated whole eggs made as described in Example XII werefried on one side, and then they were turned over. None of the yolksbroke.

EXAMPLE XV

Eggs were made as described in Example IV with the difference that thefirst bath contained 1 part by weight Anhydrous calcium chloride and 99parts water. Upon frying the eggs, their restrictive barrier seemed tobe considerably weaker than that of fried eggs made in accordance withExample IV, approaching an unacceptable level.

EXAMPLE XVI

Eggs were made as described in Example IV with the difference that thefirst bath contained 8 parts by weight Anhydrous calcium chloride and 92parts water. Upon frying the eggs, their restrictive barrier seemed tobe considerably tougher than that of fried eggs made in accordance withExample IV, approaching again an unacceptable level.

EXAMPLE XVII

Eggs were made as described in Example IV with the difference that thesecond bath contained 0.25 parts by weight Keltone HV and 99.75 partswater. Upon frying the eggs, their restrictive barrier seemed to beconsiderably weaker than that of fried eggs made in accordance withExample IV, approaching an unacceptable level.

EXAMPLE XVIII

Eggs were made as described in Example IV with the difference that thesecond bath contained 3 parts by weight Keltone HV and 97 parts water.The viscosity of the bath seemed to be undesirably high, causingexcessive quantities of solution to be transferred to the egg white.

EXAMPLE XIX

A conventional gel was made by using the ingredients in the amountsshown in Example I. After the ingredients were mixed, and heated toabout 160° F. to hydrate the starch, the mixture was poured in a moldand allowed to form a gel under static conditions (no agitation) in therefrigerator. After about 3 hours, the gel was removed from therefrigerator and introduced in the extruder to form yolks as in exampleIV. The extrudate and the yolks produced were of very irregularperipheral shape.

EXAMPLE XX

Yolks were made as described in Example IV with the difference that thetwo baths were reversed, so that the yolks were first introduced to thefilm former (sodium alginate) second bath and then to the setting agent(calcium chloride) first bath. The restrictive barriers produced in thismanner were of very non-uniform thickness and consistency. Therespective eggs, when fried, exhibited a bitter taste.

EXAMPLE XXI

A homogenized gel of simulated egg yolk material is prepared asdescribed in any one of Examples I-III and extruded through theapparatus as disclosed in FIG. 1. Instead of dropping the simulated eggyolk disk directly into the setting solution, the egg yolk disk isdropped into an edible moisture absorbing composition such as cornstarchto make the egg yolk more handable. The egg yolk disk is subsequentlysequentially transferred through the setting solution and film formingsolution to form the restrictive barrier. In addition, pursuant to thisembodiment, the size of the egg yolk disk which is extruded is somewhatsmaller in diameter than that previously described. This results in anegg yolk disk which is somewhat thicker than that previously described.The thus extruded egg yolk disk is pressed between two plates (notshown) to thin the disk and to thereby increase its diameter aftercoating with the cornstarch. This results in the simulated egg yolk diskbecoming oval-like cross-section and having a more natural appearance.

The principles, preferred embodiments, and modes of operation of thepresent invention have been described in the foregoing specification.The invention which is intended to be protected herein, however, is notto be construed as limited to the particular embodiments disclosed,since these are to be regarded illustrative rather than restrictive.Variations and changes may be made by others without departing from thespirit and scope of the invention.

What is claimed is:
 1. A simulated egg yolk comprising a mixture ofsimulated egg yolk components, said components at least including anedible liquid and a positive thermoreversible gel former, said mixturehaving been heated to above room temperature in a manner so as todissolve said gel former in said edible liquid, and subsequently havingbeen cooled in accordance with a method selected from a group consistingof (i) mixing said components continuously until said mixture forms ahomogenized gel, and (ii) forming a conventional gel, and then pureeingsaid conventional gel in a manner so as to form a homogenized gel, saidhomogenized gel having been extruded at a temperature lower than themelting point of said homogenized gel into a predetermined shape to forma shaped simulated egg yolk, said shaped egg yolk having been coatedfirst with a setting agent and then with a film former which is reactivewith said setting agent to form a restrictive barrier.
 2. The shapedsimulated egg yolk of claim 1, wherein said positive thermoreversiblegel former is present in an amount of from about 3.0-6.0 parts perhundred by weight of said edible liquid.
 3. The shaped simulated eggyolk of claim 1, wherein said positive thermoreversible gel former ispresent in an amount of from about 3.0-4.0 parts per hundred parts byweight of said edible liquid.
 4. The shaped simulated egg yolk of claim1, wherein said setting agent comprises alkaline earth ions.
 5. Theshaped simulated egg yolk of claim 1, wherein said film former comprisesan edible water soluble alginate compound.
 6. The shaped simulated eggyolk of claim 1, wherein said simulated egg yolk components furtherinclude a viscosity builder, milk solids and a colorant.
 7. A method ofmaking a simulated raw whole egg comprising preparing a shaped simulatedegg yolk using the composition of claim 1, and adding said simulated eggyolk to liquid egg white.
 8. The method of making a simulated raw wholeegg of claim 7, wherein said setting agent comprises alkaline earth ionsand said film former comprises a hydrocolloid.
 9. A simulated egg yolkcomprising a mixture of simulated egg yolk components and a restrictivebarrier encapsulating said egg yolk, said barrier formed by coating saidmixture first with a setting agent, and then, with a film former whichis reactive with said setting agent to form said barrier.
 10. Thesimulated egg yolk of claim 9, wherein said setting agent comprisesalkaline earth ions.
 11. The simulated egg yolk of claim 9, wherein saidfilm former comprises a hydrocolloid.
 12. The simulated egg yolk ofclaim 11, wherein said hydrocolloid comprises sodium alginate.
 13. Thesimulated egg yolk of claim 9, wherein said egg yolk components comprisean edible liquid, a colorant, and a viscosity modifier.
 14. Thesimulated egg yolk of claim 13, wherein said egg yolk components furtherinclude a viscosity builder and milk solids.
 15. The simulated egg yolkof claim 9, wherein said mixture is in the form of a homogenized gel ator below about room temperature.
 16. A method of making a simulated rawwhole egg comprising preparing a simulated egg yolk in accordance withclaim 9, and adding said simulated egg yolk to liquid egg white.
 17. Themethod of making a simulated raw whole egg of claim 16, furtherincluding extruding said mixture at or below about room temperature intoa predetermined shape, prior to encapsulating said yolk with saidrestrictive barrier.
 18. The method of making a simulated raw whole eggof claim 16, wherein said setting agent comprises an alkaline earth saltand said film former comprises a hydrocolloid.
 19. A method of making asimulated egg yolk comprising preparing a mixture of simulated egg yolkcomponents; heating said mixture above room temperature; then coolingsaid heated mixture in accordance with the steps selected from the groupconsisting of (i) while cooling said mixture, continuously mixing saidcomponents until said mixture forms a homogenized gel, and (ii) forminga conventional gel, and then pureeing said conventional gel in a mannerso as to form a homogenized gel; extruding and shaping said homogenizedgel to make said simulated egg yolk; and sequentially coating saidshaped egg yolk first with a setting agent and then with a film formerwhich is reactive with said setting agent to form a restrictive barrier.20. The method of making a simulated egg yolk of claim 19, wherein saidmixture is cooled during said continuous mixing to a temperature belowabout 50° F.
 21. The method of making a simulated egg yolk of claim 19,wherein said mixture is heated to a temperature in the range of fromabout 150°-180° F.
 22. The method of making a simulated egg yolk ofclaim 19, wherein said mixture includes an edible liquid and a positivethermoreversible gel former, said positive thermoreversible gel formerbeing present in the amount from about 2.5-9.0 parts per hundred partsby weight of said edible liquid.
 23. The method of making a simulatedegg yolk of claim 22, wherein said positive thermoreversible gel formeris present in the amount of from about 3.0-4.0 parts per hundred partsby weight of said edible liquid.
 24. The method of making a simulatedegg yolk of claim 22, wherein the shaping of the homogenized gelincludes a step of extruding said gel at approximately room temperatureinto a disk shape.
 25. The method of making a simulated egg yolk ofclaim 19, wherein said setting agent comprises alkaline earth ions. 26.The method of making a simulated egg yolk of claim 19, wherein said filmformer comprises a hydrocolloid.
 27. The method of making a simulatedegg yolk of claim 26, wherein said hydrocolloid comprises sodiumalginate.
 28. The method of making a simulated egg yolk of claim 19,wherein said mixture is placed in a bath containing said setting agentfor a period of less than about one minute.
 29. A method of preparing asimulated raw whole egg comprising the steps of:(a) making a mixturecomprising water, gelatin having a bloom value in the range of 200 to300 in an amount of from about 2.5-9.0 parts per hundred parts by weightof said water, freeze-thaw stable starch in an amount of from about6.0-12.0 parts per hundred parts by weight of said water, fat free milksolids in an amount of from about 4.0-8.0 parts per hundreds parts byweight of said water, a colorant and optionally a flavor; (b) raises thetemperature of said mixture until said gelatin is dissolved and saidstarch is hydrate; (c) forming a positive thermoreversible homogenizedgel by following a set of steps selected from the group consisting ofcooling said heated mixture to a temperature under 50° F. whilecontinuously mixing until said homogenized gel has been formed, andcooling said heated mixture until said mixture forms a conventional gel;and then pureeing said conventional gel in a manner to form saidhomogenized gel; (d) extruding said positive thermoreversiblehomogenized gel to form disk shaped simulated yolks; (e) applying acoating comprising calcium ions on said simulated yolks; (f) applying anadditional coating comprising sodium alginate on said yolks of step,said calcium ions setting said sodium alginate to form a restrictivebarrier; and (g) adding said yolks of step (f) to egg white.
 30. Themethod of claim 29 further comprising the step of adding egg white tosaid mixture in an amount equivalent to about 2.5-10.0 parts of eggwhite solids per hundred parts of water, said addition being made afterthe temperature of said mixture has dropped below the coagulationtemperature of said egg white.
 31. A simulated egg yolk comprising amixture of simulated egg yolk components, said simulated egg yolkcomponents having been extruded to form a shaped yolk, and a restrictivebarrier encapsulating said shaped egg yolk, said barrier having beenformed by coating said shaped egg yolk first with a setting agent, andthen, with a film former which is reactive with said setting agent toform said barrier.
 32. The simulated egg yolk of claim 31, furthercomprising a gel former.
 33. The simulated egg yolk of claim 32, whereinsaid gel former is a positive thermoreversible gel former.
 34. A methodof making a simulated egg yolk comprising the steps of:(a) forming amixture of egg components; (b) extruding said mixture to form a shapedegg product; and (c) subsequently coating said shaped egg product firstwith a setting agent, and then with a film former which is reactive withsaid setting agent to form a restrictive barrier.
 35. A method of makinga simulated egg yolk comprising the steps of:extruding a stickyhomogenized simulated egg yolk gel into an extrudate; cutting theextrudate into disks; removing the stickiness of the homogenized geldisks; and applying a restrictive barrier around said disks.
 36. Themethod of making the simulated egg yolk of claim 35, wherein said stepof removing the said stickiness of homogenized gel disks is accomplishedby contacting said homogenized gel disks with a liquid.